In CO, a person may have a loaded handgun in their car, just as they can in their home or place of business they own. Within a means of transportation, a deadly weapon that is not immediately visible to casual observers. No restriction holstered/concealed or not while in a vehicle traveling from one city to another, with or without a permit.
Part of the staute reads...
"...carrying of weapons in private automobiles or other private means of conveyance for hunting or for lawful protection of a person's or another's person or property while traveling into, through, or within, a municipal, county, or city and county jurisdiction, regardless of the number of times the person stops in a jurisdiction..."
Rifles and shotguns have different restrictions in vehicles, and must be unloaded.